NAD+

NAD+ (nicotinamide adenine dinucleotide) is a molecule every one of your cells absolutely requires — it’s essential for turning food into usable cellular energy (ATP) and for powering the enzymes responsible for DNA repair, metabolism, and immune function. NAD+ levels decline as you age, which is the basic reason there’s so much interest in restoring it. You’ll see it delivered several different ways: oral precursors (NMN and NR), IV infusion of NAD+ itself, IV infusion of NR, subcutaneous injection, and even intranasal application (though that last route has limited human data).

This is the single most important thing to understand about NAD+ therapy, and it’s genuinely underappreciated: the evidence base differs sharply depending on how it’s delivered. NAD+ itself is a large, charged molecule that can’t easily cross into your cells directly — so raising it in your bloodstream via IV doesn’t automatically translate into raising it inside your cells the way oral precursor supplements do (since your cells actively take those up and convert them internally).

Oral precursors have the strongest human evidence by far. In clinical trials, oral NR at 1,000 mg per day raised NAD+ levels in blood cells by roughly 60% after 6 weeks, and 3,000 mg per day produced roughly a 5-fold increase after 10 weeks — with good safety and tolerability at these doses. Oral NMN has multiple human randomized trials showing improved physical performance measures as well.

Direct IV NAD+ infusion, by contrast, has much more limited controlled human data, and what exists suggests a real tolerability tradeoff: a 2026 study comparing IV NAD+ to IV NR found NAD+ infusions caused more nausea, malaise, sweating, stomach cramping, and headache, and took meaningfully longer to complete. If you’re specifically comparing routes, that’s a genuinely useful, hard-to-find piece of information.

NAD+ is not FDA-approved for any indication. NMN and NR are legally available as over-the-counter dietary supplements in the U.S. Injectable NR chloride has been under FDA 503B Bulk Drug Substances Category 1 evaluation since December 2022. IV and subcutaneous NAD+ administration should only be done under medical supervision given its documented reaction profile. This page describes research findings only and is not a claim about effects in humans or an offer to treat any condition.

Oral NMN and NR currently have the strongest human clinical trial evidence, with multiple randomized controlled trials demonstrating dose-dependent NAD+ elevation and good tolerability. IV NAD+ has comparatively limited controlled human data, and a real mechanistic question exists about whether raising extracellular NAD+ via IV meaningfully raises intracellular NAD+ compared to precursor-based approaches. Which is right for you depends on your goals and health history, which our providers evaluate individually.

Oral precursors have a well-characterized safety profile at doses up to 3,000 mg/day of NR in trial data. IV NAD+ has a more pronounced reaction profile (nausea, sweating, headache, and rate-dependent discomfort) and should only be administered under medical supervision with a gradual infusion rate.